Evidentials are used in Kareyku to mark how evident one statement is or the source of said statement. Only one evidential marker can be used each time, and they can be used either with verbs, adjectives or nouns. There are seven evidentials in Kareyku:
-s, -si Determines that the statement is fact either empiric or to the speaker.
-n, -ni Determines that the speaker heard about the statement.
-ch, -chi Determines that the speaker assumes the statement to be true.
-l, -li Determines that the thing being referred is famous for doing what is stated.
-sha Determines that the speaker "believes" the statement to be true.
-lya Determines that the thing being referred is infamous for doing what is stated.
-lcha Determines that the statement is obvious.
So for instance, if we have the previous example sentence: qappaka pile 'I eat fish'. We can further develop it into:
qappakas pile. I eat fish (it's a fact, I'm doing it).
qappakan pile. I eat fish (I have heard, I don't remember).
qappakach pile. I eat fish (I assume, because I'm eating it).
qappakal pile. I eat fish! (I'm famous for that!)
qappakasha pile. I believe I eat fish.
qappakalya pile. I eat fish (I'm infamous for it, because I eat too much or I don't finish them).
qappakalcha pile. I eat fish (duh! It's obvious!)
Evidentials have an active role in formality and informality contrast and in politeness vs. rudeness. For instance, it is considered in Kareyku culture that you should not always be sure of things you say, even when talking about yourself the continuous use of the "fact evidential" can result in rudeness. The rudest of them all, of course, is the "obvious evidential" which is considered very aggressive and rude, you should never point out to others they don't know something, even when you are right or even if the fact is really obvious.
The case with the "infamous evidential" is interesting. It used to be a respectful or augmentative equivalent of the "famous evidential" but as time passed it started to be felt pompous and so developed as a satirical comment, thus infamity for doing something too much.